Wave properties

Question 1

Transverse waves

Answer 1

The oscillations are perpendicular to the direction of energy transfer.

Question 2

Longitudinal waves

Answer 2

The oscillations are parallel to the directions of energy transfer.

Question 3

Examples of transverse waves

Answer 3

.All electromagnetic waves
.ripples and waves in water

Question 3

Examples of longitudinal waves

Answer 3

.sound waves in air, ultrasound
.shock waves.

Question 3

What is wave speed?

Answer 3

the speed at which the energy is being transferred

Question 4

How do you find the wave speed?

Answer 4

frequency x wavelength

Question 4

Amplitude

Answer 4

The maximum displacement of a point on the wave from its undisturbed position.

Question 5

Wavelength

Answer 5

The distance between the same point on 2 waves.

Question 6

Frequency

Answer 6

The number of complete waves passing a certain point per second.
.measured in hertz.

Question 7

What are the 3 things that can happen when a wave arrive at a boundary between 2 different materials?

Answer 7

-Absorbed
-Transmitted
-Reflected
This all depends on the wavelength and the properties of the materials invloved.

Question 8

What is the rule of all reflected waves?

Answer 8

Angle of incidence = angle of reflection

Question 9

What is the ‘Angle of incidence’?

Answer 9

The angle between the incoming wave and the normal.

Question 10

What is the ‘Angle of reflection’?

Answer 10

The angle between the reflected wave and the normal.

Question 11

What is the ‘Normal’?

Answer 11

An imaginary line that is perpendicular to the surface at the point of incidence.

Question 12

What are the 2 types of reflection?

Answer 12

Specular and diffuse

Question 13

Specular reflection

Answer 13

-boundary is flat
-normals are in the same direction
-produce a clear image

Question 14

Diffuse reflection

Answer 14

-boundary is bumpy
-normals will all be different
-appears matte

Question 15

Refraction

Answer 15

Wave changes direction as they pass 1 medium to another.

Question 16

Why does refraction occur?

Answer 16

Waves travel at different speed in different mediums.
higher density = slower the wave

Question 17

What happens if the light wave enters perpendicular into the boundary

Answer 17

It will carry on in the same direction

Question 18

What happens if the light wave enters the boundary at an angle

Answer 18

The light wave will change direction - it has been refracted and bend towards the normal (if boundary is more dense)

Question 19

Sound waves

Answer 19

Vibrations that pass through the molecules of a medium

Question 20

How do sound waves travel?

Answer 20

Ina series of compressions and rarefractions

Question 20

Compressions

Answer 20

Regions where the particles are close together

Question 21

Rarefractions

Answer 21

Regions where the particles are furthest apart

Question 22

Does sound waves travel faster through more denser objects or loose?

Answer 22

More densely packed

Question 23

Why cant sound travel through space

Answer 23

Because space is a vaccum (no particles to move or vibrate)

Question 24

Sound waves frequency travelling through different medium doesn't change but ____?

Answer 24

If the speed is increasing the Wavelength must be increasing

Question 25

What can sound wave do?

Answer 25

- Reflected (echos) - Absorbed - Refracted

Question 26

Name parts of the eara in order

Answer 26

- Ear canal - Ear drums - Ossicles (group of 3 small bones) - semicircular canals - cochlea - auditory nerve (to brain)

Question 27

How human hearing works

Answer 27

1. Sound waves travels through ear canal and reaches the ear drums causing it to vibrate 2. These vibrations will be transmitted through the tiny bones (ossicles) 3. Through the semicircle canals 4. Then into the cochlea which converts the vibrations into electrical signals 5. Electrical signals get sent through auditory nerves to the brain

Question 28

Higher frequencies =

Answer 28

Higher pitch

Question 29

Lower frequencies =

Answer 29

Lower pitch

Question 30

Higher amplitude =

Answer 30

Louder

Question 31

Lower amplitude =

Answer 31

Quieter

Question 32

On average how much can a human hear (Hz)

Answer 32

20Hz to 20,000 Hz

Question 33

Factors that effect hearing

Answer 33

- Age (wearing and tearing of cochlea and auditory nerve)

Question 34

Ultrasound

Answer 34

Sound with frequencies higher than 20000Hz

Question 35

How do humans make ultrasound?

Answer 35

Increase the electrical oscillations of speakers

Question 36

Partial reflection

Answer 36

When ultra sound hits a boundary between 2 different mediums and and some of the waves are refracted while some are reflected

Question 37

How can you find out how far away a boundary is by ultrasound?

Answer 37

- Speed of the wave - Time it take to be reflected